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<h2><span class="refentrytitle">Macro BOOST_VARIANT_ENUM_PARAMS</span></h2>
<p>BOOST_VARIANT_ENUM_PARAMS — Enumerate parameters for use with
        <code class="computeroutput"><a class="link" href="boost/variant.html" title="Class template variant">variant</a></code>.</p>
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<h2 class="refsynopsisdiv-title">Synopsis</h2>
<div class="refsynopsisdiv"><pre class="synopsis"><span class="comment">// In header: &lt;<a class="link" href="variant/reference.html#header.boost.variant.variant_fwd_hpp" title="Header &lt;boost/variant/variant_fwd.hpp&gt;">boost/variant/variant_fwd.hpp</a>&gt;

</span>BOOST_VARIANT_ENUM_PARAMS(param)</pre></div>
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<a name="id-1.3.44.5.4.4.4"></a><h2>Description</h2>
<p> Expands to variadic template list in the following manner:
        <code class="computeroutput"><pre class="programlisting">
            <span class="identifier">BOOST_VARIANT_ENUM_PARAMS</span><span class="special">(</span><span class="identifier">T</span><span class="special">)</span>                    <span class="special">=</span><span class="special">&gt;</span> <span class="identifier">T0</span><span class="special">,</span> <span class="identifier">TN</span><span class="special">...</span>
            <span class="identifier">BOOST_VARIANT_ENUM_PARAMS</span><span class="special">(</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">)</span>              <span class="special">=</span><span class="special">&gt;</span> <span class="keyword">class</span> <span class="identifier">T0</span><span class="special">,</span> <span class="keyword">class</span><span class="special">...</span> <span class="identifier">TN</span>
            <span class="identifier">BOOST_VARIANT_ENUM_PARAMS</span><span class="special">(</span><span class="keyword">class</span> <span class="identifier">Something</span><span class="special">)</span>      <span class="special">=</span><span class="special">&gt;</span> <span class="keyword">class</span> <span class="identifier">Something0</span><span class="special">,</span> <span class="keyword">class</span><span class="special">...</span> <span class="identifier">SomethingN</span>
            <span class="identifier">BOOST_VARIANT_ENUM_PARAMS</span><span class="special">(</span><span class="keyword">typename</span> <span class="identifier">Something</span><span class="special">)</span>   <span class="special">=</span><span class="special">&gt;</span> <span class="keyword">typename</span> <span class="identifier">Something0</span><span class="special">,</span> <span class="keyword">typename</span><span class="special">...</span> <span class="identifier">SomethingN</span>
            <span class="identifier">BOOST_VARIANT_ENUM_PARAMS</span><span class="special">(</span><span class="identifier">Something</span><span class="special">)</span>            <span class="special">=</span><span class="special">&gt;</span> <span class="identifier">Something0</span><span class="special">,</span> <span class="identifier">SomethingN</span><span class="special">...</span>
            <span class="identifier">BOOST_VARIANT_ENUM_PARAMS</span><span class="special">(</span><span class="identifier">Something</span><span class="special">)</span>            <span class="special">=</span><span class="special">&gt;</span> <span class="identifier">Something0</span><span class="special">,</span> <span class="identifier">SomethingN</span><span class="special">...</span>
        </pre></code>
      </p>
<p>
        Otherwise expands to a comma-separated sequence of length
        <code class="computeroutput">BOOST_VARIANT_LIMIT_TYPES</code>, where
        each element in the sequence consists of the concatenation of
        <span class="emphasis"><em>param</em></span> with its zero-based index into the
        sequence. That is,
        <code class="computeroutput">param ## 0, param ## 1, ..., param ## BOOST_VARIANT_LIMIT_TYPES - 1</code>.</p>
<p><span class="bold"><strong>Rationale</strong></span>: This macro greatly
        simplifies for the user the process of declaring
        <code class="computeroutput"><a class="link" href="boost/variant.html" title="Class template variant">variant</a></code> types
        in function templates or explicit partial specializations of class
        templates, as shown in the
        <a class="link" href="variant/tutorial.html#variant.tutorial.preprocessor" title="Preprocessor macros">tutorial</a>.</p>
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<div class="copyright-footer">Copyright © 2002, 2003 Eric Friedman, Itay Maman<br>Copyright © 2014-2024 Antony Polukhin<p>Distributed under the Boost Software License, Version 1.0.
    (See accompanying file <code class="filename">LICENSE_1_0.txt</code> or copy at 
    <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
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